Tire Tread Coextrusion with THz Thickness Control

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Solution Overview

Problem

Current tire tread manufacturing processes face challenges in achieving sub-millimeter precision in layer thickness and controlled rubber compositions, with radar technology for tread thickness measurements having significant limitations.

Innovation Solution

A tire tread production line that includes a coextruder for forming multi-layer tire treads, equipped with THz sensors to irradiate and analyze the extrudate with terahertz electromagnetic radiation, allowing for precise thickness determination and real-time control of the extrusion process using a controller, along with the option to add refractive index modifiers like carbon black or titanium dioxide to enhance interface detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar technology is used for tread thickness measurements, then measurement capability is provided, but measurement precision is insufficient for sub-millimeter requirements

Engineering Contradiction:
Improvetread thickness measurement precisionVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the measurement parameter from microwave/radar frequency to terahertz frequency range (0.1-10 THz). This parameter change enables sub-millimeter precision thickness measurements by utilizing the shorter wavelength and higher frequency electromagnetic radiation, which provides better resolution for detecting thin rubber layers and interfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional radar/microwave measurement systems with terahertz electromagnetic radiation systems. This substitution provides superior measurement capability for rubber thickness because THz radiation interacts more effectively with rubber materials at the required sub-millimeter scale, enabling precise thickness and composition control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If multiple rubber compositions are coextruded to form multi-layer treads, then tire performance is improved, but manufacturing precision becomes difficult to control

Engineering Contradiction:
Improvetire performance optimizationVSAvoidlayer thickness control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent implements real-time feedback control by continuously measuring the thickness and composition of each extruded layer using terahertz sensors during the coextrusion process. The measurement data is fed back to the control system, which automatically adjusts extrusion parameters (temperature, pressure, screw speed) to maintain precise layer thickness control despite variations in rubber composition and processing conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The terahertz measurement system serves multiple functions: it measures thickness of individual layers, detects composition variations, identifies layer interfaces, and provides feedback for process control. This multi-functionality enables precise control of multi-layer coextrusion processes while maintaining the ability to optimize tire performance through different rubber compositions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If conventional extrusion processes are used, then production efficiency is maintained, but thickness precision cannot achieve sub-millimeter levels

Engineering Contradiction:
Improvelayer thickness precisionVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent implements preliminary action by establishing real-time measurement and feedback control during the extrusion process itself, rather than relying on post-manufacturing inspection and adjustment. The terahertz sensors continuously monitor layer thickness as the rubber is being extruded, allowing immediate corrections to be made while the process is running, thus achieving sub-millimeter precision without slowing down production.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent maintains continuous operation of the extrusion process with uninterrupted real-time measurement and control. The terahertz measurement system operates continuously during extrusion, and the feedback loop runs without interruption, allowing the production line to maintain high efficiency while achieving precise thickness control through continuous monitoring and adjustment rather than batch-wise or post-process corrections.

Inventive Principle:
Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the production of tire treads with sub-millimeter precision in layer thickness, improving tire uniformity and performance by providing real-time feedback and adjustments during the manufacturing process.

Implementation Method 1

The THz sensor is configured to irradiate the multi-layer tire tread extrudate with THz electromagnetic radiation, and receiving a response of the multi-layer tire tread extrudate to the THz electromagnetic radiation

Methodology Applied
Scientific EffectTHz electromagnetic radiation reflection: Reflection

Implementation Method 2

The response of the multi-layer tire tread extrudate to the THz electromagnetic radiation preferably comprises one or more echoes of the THz electromagnetic radiation, the one or more echoes being reflection and/or transmission of the THz electromagnetic radiation on one or more interfaces of the multi-layer tire tread extrudate

Methodology Applied
Scientific EffectTHz electromagnetic radiation transmission: Refraction

Implementation Method 3

a controller operatively connected to the coextruder and to the THz sensor, the controller being configured to operate the coextruder based on the response of the multi-layer tire tread extrudate to the THz electromagnetic radiation

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP4335612A1Tire tread production line and method for manufacturing a tire tread
Publication Date: 2024.03.13 THE GOODYEAR TIRE & RUBBER CO
  • EP4335612A1 patent drawingFigure 1
  • EP4335612A1 patent drawingFigure 2
  • EP4335612A1 patent drawingFigure 3

AI summary

A tire tread production line and a method for manufacturing a tire tread is disclosed. The production line comprises: a coextruder (12) for coextruding at least two rubber compositions, the coextruder (12) comprising at least two feeding inlets (22) for receiving the at least two rubber compositions, the coextruder (12) further comprising one or at least two screws (24) for driving the received at least two rubber compositions, an extrusion die (26) for forming a multi-layer tire tread extrudate (128), the one or the at least two screws (24) being configured to drive the at least two rubber compositions in the extrusion die (26); a THz sensor (14), the THz sensor being configured to irradiate the multi-layer tire tread extrudate (28) with THz electromagnetic radiation, and receiving a response of the multi-layer tire tread extrudate (28) to the THz electromagnetic radiation; and a controller (18) operatively connected to the coextruder (12) and to the THz sensor (14), the controller (18) being configured to operate the coextruder (12) based on the response of the multi-layer tire tread extrudate (28) to the THz electromagnetic radiation.